81241493 has 2 divisors, whose sum is σ = 81241494. Its totient is φ = 81241492.

The previous prime is 81241439. The next prime is 81241507. The reversal of 81241493 is 39414218.

It is a happy number.

Together with previous prime (81241439) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42016324 + 39225169 = 6482^2 + 6263^2 .

It is a cyclic number.

It is not a de Polignac number, because 81241493 - 2¹⁰ = 81240469 is a prime.

It is a super-3 number, since 3×81241493³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81241403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40620746 + 40620747.

It is an arithmetic number, because the mean of its divisors is an integer number (40620747).

Almost surely, 2^81241493 is an apocalyptic number.

It is an amenable number.

81241493 is a deficient number, since it is larger than the sum of its proper divisors (1).

81241493 is an equidigital number, since it uses as much as digits as its factorization.

81241493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 32.

The square root of 81241493 is about 9013.4062928507. The cubic root of 81241493 is about 433.1044360484.

The spelling of 81241493 in words is "eighty-one million, two hundred forty-one thousand, four hundred ninety-three".